How to save the correct rotated image using camerax Front Camera?

Question

I am using CameraX for developing my android application in which when I take the pricture in landscape mode or portrait mode the image captured and saved is mirror image.

I know that FRONT camera works in the same way. But what to do if I want to save the picture in the same way it was taken?

Here is the buildUseCase() Code I am using:

private fun buildUseCases() {

        val screenAspectRatio = Rational(width, height)
        val screenTargetRotation = display.rotation

        //Preview
        val previewConfig = PreviewConfig.Builder().apply {
            setTargetAspectRatio(screenAspectRatio)
            setTargetRotation(screenTargetRotation)
            setLensFacing(lensFacing)
        }.build()

        preview = AutoFitPreviewBuilder.build(previewConfig, this)
        //End - Preview


        // Set up the capture use case to allow users to take photos
        val imageCaptureConfig = ImageCaptureConfig.Builder().apply {
            setTargetAspectRatio(screenAspectRatio)
            setTargetRotation(screenTargetRotation)
            setLensFacing(lensFacing)
            setCaptureMode(ImageCapture.CaptureMode.MAX_QUALITY)
        }.build()


        imageCapture = ImageCapture(imageCaptureConfig)
    }

Please help me with what to change to get correct image captured.

Note: The camera facing is FRONT and it is in Landscape mode.

Answer 1

You need to read EXIF data of the image created & have to write your own custom controllers as per requirements & needs. It's very normal in most Android & iOS devices that the captured images get rotated & it must be handled accordingly. In most of the devices, the default orientation of the camera is set to landscape mode, so even if you take a pic in portrait mode it gets rotated to 90degrees.

From EXIF data, you can get the degree of the image rotated or if its mirrored & then you can handle it in the backend.

To rotate your image you can try

private static Bitmap rotateImageIfRequired(Bitmap img, Uri selectedImage) throws IOException 
{
    ExifInterface ei = new ExifInterface(selectedImage.getPath());
    int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

    switch (orientation) {
        case ExifInterface.ORIENTATION_ROTATE_90:
            return rotateImage(img, 90);
        case ExifInterface.ORIENTATION_ROTATE_180:
            return rotateImage(img, 180);
        case ExifInterface.ORIENTATION_ROTATE_270:
            return rotateImage(img, 270);
        default:
            return img;
    }
 }

private static Bitmap rotateImage(Bitmap img, int degree)
{
    Matrix matrix = new Matrix();
    matrix.postRotate(degree);
    Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
    img.recycle();
    return rotatedImg;
}

For the image flipping issue you can try this

public static Bitmap flip(Bitmap src, int type) 
{
     // create new matrix for transformation
     Matrix matrix = new Matrix();
     matrix.preScale(-1.0f, 1.0f);

     // return transformed image
     return Bitmap.createBitmap(src, 0, 0, src.getWidth(), src.getHeight(), matrix, true);
 }

And then set the image to ImageView as

imgPreview.setImageBitmap(flip(bitmap));